AUSTIN, Texas – “I love you, Joy!” a man in the front row screams as the Civil Wars take the AMD stage Sunday afternoon (Oct. 14) at the Austin City Limits music festival. For good measure, he immediately adds: “Oh, and I love you, too, John Paul! Seriously!”

Love. No better word suits Joy Williams and John Paul White. I’ve been writing about music for nearly two decades now and have never seen two people so simply in love with their job, so joyful about their music, so happy to be singing together. Beautiful. Every moment.

Multiply that by the adoring thousands here and imagine.

The Civil Wars’ astonishment at the mass affection is palpable. “My goodness,” Williams mouths as the duo takes the stage. She smiles. Bows her head.

No wonder she’s overwhelmed. I discovered the Civil Wars just two South by Southwests ago. We were in the tiny back room at Threadgill’s. Probably 60 people sat around. Seemed like only those few knew them, but Radney Foster sure did and was highly vocal about it. The celebrated songwriter sat beside me during their gig, slapping my leg every time harmonies matched perfectly and hooted and hollered their praises to anyone who would listen.

I went home with a sore leg. Foster was onto something.

The Civil Wars absolutely illuminate the day at ACL. They certainly benefited from the intimacy at Threadgill’s two years ago but they’re equally potent in a festival setting. Fans go wild as they deliver high watermarks like “Barton Hollow” and “Forget Me Not.”

Meanwhile, the Lumineers pack the Austin Ventures stage tighter than I’ve seen in any year and the Avett Brothers follow the Civil Wars with similarly stunning results.

Sunday brought clear skies again and smiling faces all around. This is why I moved here six years ago from Denver. Beautiful people enjoying the festival with egos freed and minds awake. Ignore the rain from Saturday. Mud turned to dirt on the festival’s final day. No problems existed. A fact now fairly widely known: The Austin City Limits Music Festival might be the most fulfilling three days under the sun for music lovers. On Sunday, it showed it without a doubt.

Actually, make that six days under the sun and probably more. The big news this year: ACL expands to two consecutive weekends next year. Organizers say the bands will be 90 percent the same each weekend and the festival will spotlight more local acts. Imagine the after-parties the week between if bands stick around.